Method of tracing corrosive materials

ABSTRACT

A method of using an inert fluorescent tracer in an industrial water system wherein the water of said industrial water system contains a certain amount of a corrosive material, is described and claimed, as is a method of using an inert fluorescent tracer to trace the corrosive material itself. Combinations of inert fluorescent tracers in corrosive materials are also described and claimed.

FIELD OF INVENTION

This invention is in the field of industrial water systems.Specifically, this invention is in the field of the use of fluorescenttracers in the water of an industrial water system where significantamounts of a corrosive material are present.

BACKGROUND OF THE INVENTION

Industrial water systems exist so that necessary chemical, mechanicaland biological processes can be conducted to reach the desired outcome.Industrial water systems include the following: cooling water systems,including open recirculating, closed and once-through cooling watersystems; boilers and boiler water systems; petroleum wells, downholeformations, geothermal wells and other oil field applications; mineralprocess waters including mineral washing, flotation and benefaction;paper mill digesters, washers, bleach plants and white water systems;black liquor evaporators in the pulp industry; gas scrubbers and airwashers; continuous casting processes in the metallurgical industry; airconditioning and refrigeration systems; industrial and petroleum processwater; indirect contact cooling and heating water, such aspasteurization water; water reclamation and purification systems;membrane filtration water systems; food processing streams (meat,vegetable, sugar beets, sugar cane, grain, poultry, fruit and soybean);and waste treatment systems as well as in clarifiers, liquid-solidapplications, municipal sewage treatment and industrial or municipalwater systems.

While water is obviously the major component of an industrial watersystem there are typically other materials present in an industrialwater system. These can include anything from innocuous materials allthe way to highly corrosive materials. A corrosive material can beanything that attacks building materials or metals or anything thatburns, irritates or destructively attacks organic tissues. Corrosivematerials can be in the category of unwanted impurities or they can bepresent in the water in order to perform a needed function.

As is the case with many industrial water systems, many cooling watersystems use treatment products to control undesirable phenomena such asscaling, corrosion, fouling and microbiological growth. These treatmentproducts include chemical materials such as polymers, phosphates,phosphonates, azoles, zinc, molybdate, biocides, and other materials andare known to people of ordinary skill in the art of cooling watersystems.

Treatment products are typically prepared by taking these chemicalmaterials and formulating them into aqueous liquid phase products orsolid products for distribution to and delivery into an industrial watersystem. Delivery into an industrial water system, can be accomplished bypump feed or edductor feed system for a liquid product, by solid productfeeder for a solid product or even by manual addition of the treatmentproduct for either liquid or solid product. A cooling water system, forexample, can be set up to feed treatment product based on either ableed/feed mechanism where the action of blowdown triggers a chemicalfeed pump or valve that feeds treatment product; or, in the alternative,the cooling water system feeds treatment product based on timers using a“feeding schedule” or flow meters on the make-up water line trigger thepumping of treatment product based on a certain amount of make-up waterbeing pumped. A limitation of these control methods is that none ofthese systems measure the treatment product concentration directlyonline, so if there is a mechanical problem, for example, if a pumpfails, a drum empties, or high, low or unknown blowdown occurs, systemvolume changes or makeup water quality changes; the correct treatmentproduct concentration is not maintained. Because this problem is common,cooling tower systems are typically either overfed with treatmentproduct to ensure the level of treatment product in the system does notdrop too low as a result of high variability in product dosage or thetreatment product is unknowingly underfed. Both overfeeding andunderfeeding of treatment product are undesirable due to cost andperformance drawbacks.

One aspect of known control schemes is addition of an inert fluorescentchemical tracer in a known proportion to the active component of thetreatment product and feeding this mixture of treatment product andtracer to the cooling water system. Then a fluorometer is used tomonitor the fluorescent signal of the inert fluorescent chemical. Thistechnology is commercially available as TRASAR®, which is a registeredtrademark of Ondeo Nalco Company, Ondeo Nalco Center, 1601 W. DiehlRoad, Naperville Ill. 60563, (630) 305-1000.

The fluorescent signal of the inert fluorescent chemical is used todetermine how much inert fluorescent tracer is present, and by knowingthe amount of inert fluorescent tracer that is present it is possible todetermine the amount of treatment product that is present in the coolingtower. If the amount of treatment product that is present is not what isdesired then the feed rate of treatment product can be adjusted toprovide the desired amount of treatment product.

A known difficulty with the use of inert fluorescent tracers inindustrial water systems is the susceptibility of some of them todegradation of their fluorescent signal upon contact, for a sufficientlength of time, with corrosive materials. It would be desirable to haveinert fluorescent tracers that are capable of maintaining theirfluorescent signal in the presence of common corrosive materials.

SUMMARY OF THE INVENTION

The first aspect of the instant claimed invention is a method of usingan inert fluorescent tracer in an industrial water system wherein thewater of said industrial water system contains a certain amount of acorrosive material, comprising the steps of:

-   -   1) providing an industrial water system wherein the water of        said industrial water system contains a certain amount of a        corrosive material;    -   2) adding to the water of said industrial water system a        treatment chemical wherein said treatment chemical includes an        inert fluorescent tracer in a known proportion;    -   3) providing a fluorometer capable of detecting the fluorescent        signal of said inert fluorescent tracer, wherein said        fluorometer has a sample cell that corrosive materials can be        placed in without rendering the sample cell unusable;    -   b 4) using said fluorometer to detect and measure the        fluorescent signal of said fluorescent tracer in the water of        said industrial water system;    -   b 5) using the detected and measured fluorescent signal to        determine how much of the treatment chemical is present in the        water of said industrial water system; and optionally;    -   6) adjusting the operating parameters of said industrial water        system such that the amount of treatment chemical present is        optimal for the operating conditions of said industrial water        system.

The second aspect of the instant claimed invention is a method oftracing a corrosive material, comprising the steps of:

-   -   (a) providing an industrial water system and a corrosive        material that will be added to the water of the industrial water        system;    -   (b) placing in said corrosive material an inert fluorescent        tracer which has a detectable fluorescent signal when placed in        said corrosive material, wherein said inert fluorescent tracer        is added to said corrosive material in a known proportion;    -   (c) adding said corrosive material containing an inert        fluorescent tracer to the water of said industrial water system;    -   (d) providing a fluorometer capable of detecting the fluorescent        signal of said inert fluorescent tracer, wherein said        fluorometer has a sample cell that corrosive materials can be        placed in without rendering the sample cell unusable;    -   (e) using said fluorometer to detect and measure the fluorescent        signal of said fluorescent tracer in the water of said        industrial water system;    -   (f) using the detected and measured fluorescent signal to        determine how much of the corrosive material is present in the        water of said industrial water system; and optionally    -   (g) adjusting the operating parameters of said industrial water        system such that the amount of corrosive material present is        optimal for the operating conditions of said industrial water        system.

The third aspect of the instant claimed invention is a composition ofmatter comprising

-   -   a) from about 0.01 ppm to about 10,000 ppm of a compound        selected from the group consisting of 1,3,6,8-pyrene        tetrasulfonic acid and the known salts of 1,3,6,8-pyrene        tetrasulfonic acid; and    -   b) a corrosive material, wherein said corrosive material is        selected from the group consisting of concentrated HCl,        concentrated H₂SO₄, glacial acetic acid, concentrated H₃PO₄ and        dimethylformamide; wherein concentrated HCl is at least about 37        wt. % HCl in water, concentrated H₂SO₄ is at least about 98 wt.        % H₂SO₄ in water, wherein concentrated H₃PO₄ is at least about        85 wt. % H₃PO₄ in water; wherein glacial acetic acid is at least        about 100 wt. % acetic acid in water and wherein        dimethylformamide is about 100 wt. % dimethylformamide.

The fourth aspect of the instant claimed invention is a composition ofmatter comprising

-   -   a) from about 0.01 ppm to about 10,000 ppm of a compound        selected from the group consisting of 1,5-naphthalenedisulfonic        acid and the known salts of 1,5-naphthalenedisulfonic acid, and    -   b) a corrosive material, wherein said corrosive material is        selected from the group consisting of concentrated HCl and        concentrated H₃PO₄; wherein concentrated HCl is at least about        37 wt. % HCl in water and wherein concentrated H₃PO₄ is at least        about 85 wt. % H₃PO₄ in water.

The fifth aspect of the instant claimed invention is a composition ofmatter comprising

-   -   a) from about 0.01 ppm to about 10,000 ppm of a compound        selected from the group consisting of isomers of anthracene        disulfonic acid and salts thereof and    -   b) a corrosive material, wherein said corrosive material is        selected from the group consisting of concentrated HCl,        concentrated H₃PO₄ and dimethylformamide; wherein concentrated        HCl is at least about 37 wt. % HCl in water, wherein        concentrated H₃PO₄ is at least about 85 wt. % H₃PO₄ in water and        wherein dimethylfornamide is about 100 wt. % dimethylformamide.

DETAILED DESCRIPTION OF THE INVENTION

Throughout this patent application the following terms have theindicated definitions:

“CAS #” refers to the Chemical Abstracts Services Registry Number.

Nalco refers to Ondeo Nalco Company, Ondeo Nalco Center, 1601 W. DiehlRoad, Naperville Ill. 60563, telephone number (630) 305-1000.

The first aspect of the instant claimed invention is a method of usingan inert fluorescent tracer in an industrial water system wherein thewater of said industrial water system contains a certain amount of acorrosive material, comprising the steps of:

-   -   a) providing an industrial water system wherein the water of        said industrial water system contains a certain amount of a        corrosive material;    -   b) adding to the water of said industrial water system a        treatment chemical wherein said treatment chemical includes an        inert fluorescent tracer in a known proportion;    -   c) providing a fluorometer capable of detecting the fluorescent        signal of said inert fluorescent tracer, wherein said        fluorometer has a sample cell that corrosive materials can be        placed in without rendering the sample cell unusable;    -   d) using said fluorometer to detect and measure the fluorescent        signal of said fluorescent tracer in the water of said        industrial water system;    -   e) using the detected and measured fluorescent signal to        determine how much of the treatment chemical is present in the        water of said industrial water system; and optionally;    -   f) adjusting the operating parameters of said industrial water        system such that the amount of treatment chemical present is        optimal for the operating conditions of said industrial water        system.

Industrial water systems include the following: cooling water systems,including open recirculating, closed and once-through cooling towerwater systems; boilers and boiler water systems; petroleum wells,downhole formations, geothermal wells and other oil field applications;mineral process waters including mineral washing, flotation andbenefaction; paper mill digesters, washers, bleach plants and whitewater systems; black liquor evaporators in the pulp industry; gasscrubbers and air washers; continuous casting processes in themetallurgical industry; air conditioning and refrigeration systems;industrial and petroleum process water; indirect contact cooling andheating water, such as pasteurization water; water reclamation andpurification systems; membrane filtration water systems; food processingstreams (meat, vegetable, sugar beets, sugar cane, grain, poultry, fruitand soybean); and waste treatment systems as well as in clarifiers,liquid-solid applications, municipal sewage treatment and industrial ormunicipal water systems.

Treatment chemicals for use in industrial water systems includecommercially available corrosion inhibitors, biological control agents,scale inhibitors, dispersants, coagulants, flocculants, and pH controlagents. These commercially available products are well known to peoplein the art of industrial water chemistry.

1,3,6,8-pyrene tetrasulfonic acid and the known salts of 1,3,6,8-pyrenetetrasulfonic acid are inert fluorescent tracers that may be used withlarge amounts of concentrated HCl, concentrated H₂SO₄, glacial aceticacid, concentrated H₃PO₄ and dimethylformamide; wherein concentrated HClis at least about 37 wt. % HCl in water, concentrated H₂SO₄ is at leastabout 98 wt. % H₂SO₄ in water, wherein concentrated H₃PO₄ is at leastabout 85 wt. % H₃PO₄ in water; wherein glacial acetic acid is at leastabout 100 wt. % acetic acid in water and wherein dimethylformamide isabout 100 wt. % dimethylformamide. The preferred known salt of1,3,6,8-pyrene tetrasulfonic acid for use with corrosive materials isthe tetrasodium salt. This material is available from Nalco.

1,5-naphthalenedisulfonic acid and the known salts of1,5-naphthalenedisulfonic acid disodium salt may be used in watercontaining large amounts of concentrated HCl and concentrated H₃PO₄;wherein concentrated HCl is at least about 37 wt. % HCl in water andwherein concentrated H₃PO₄ is at least about 85 wt. % H₃PO₄ in water.The preferred known salt of 1,5-naphthalenedisulfonic acid for use withcorrosive materials is the disodium salt. This material is availablefrom Nalco.

Isomers of anthracene disulfonic acid and salts thereof, may be used inwater containing large amounts of concentrated HCl, concentrated H₃PO₄and dimethylformamide; wherein concentrated HCl is at least about 37 wt.% HCl in water, wherein concentrated H₃PO₄ is at least about 85 wt. %H₃PO₄ in water and wherein dimethylformamide is about 100 wt. %dimethylformamide.

Known isomers of anthracene disulfonic acid, and certain of their knownsalt forms include the following:

-   -   CAS # 13189-75-8 1,5-anthracene disulfonic acid, sodium salt;    -   CAS # 55750-36-2 1,8-anthracene disulfonic acid sodium salt;    -   CAS # 61736-91-2 1,5-anthracene disulfonic acid;    -   CAS # 61736-92-3 1,8-anthracene disulfonic acid;    -   CAS # 61736-67-2 1,5-anthracene disulfonic acid, magnesium salt;    -   CAS # 61736-93-4 1,6-anthracene disulfonic acid;    -   CAS # 61736-94-6 1,7-anthracene disulfonic acid;    -   CAS# 61736-95-6 2,6-anthracene disulfonic acid; and    -   CAS# 61736-96-7 2,7-anthracene disulfonic acid.

The preferred isomers of anthracene disulfonic acid are 1,5-anthracenedisulfonic acid, magnesium salt, 1,5-anthracene disulfonic acid, sodiumsalt and 1,8-anthracene disulfonic acid sodium salt and mixturesthereof. The most preferred isomer of anthracene disulfonic acid isabout a 2:1 mixture of 1,5-anthracene disulfonic acid, sodium salt and1,8-anthracene disulfonic acid sodium salt.

Isomers of anthracene disulfonic acid and their known salts can beobtained by following synthetic techniques known in the art of organicchemistry. See GB 1214256, A method of preparing anthraquinone1,5-disulphonic acid, published Oct. 13, 1976, assigned to ImperialChemical Industries, Studies on the Sulfonation of Anthracene. Part 1.Sulfonation in neutral or basic solvents, by John O. Morley, Journal ofthe Chemical Society, Perkin Transactions 2: Physical Organic Chemistry(1972-1999) (1976), (13), 1554-9, Studies on the Sulfonation ofAnthracene. Part 2. Sulfonation in acetic acid and related solvents, byJohn O. Morley, Journal of the Chemical Society, Perkin Transactions 2:Physical Organic Chemistry (1972-1999) (1976), (13), 1560-4.

Fluorometers suitable for use in the instant claimed invention arecommercially available from Nalco, these include: TRASAR® 8000, TRASARO®3000, Xe-2 Fluorometer and a TRASAR® 350. Other suitable fluorometersare available from Spex. The preferred fluorometers are a TRASARO® 3000unit and a TRASARS® Xe-2 Fluorometer.

How to set up and program a fluorometer and use it to measure thefluorescent signal of a fluorescent tracer is known to people ofordinary skill in the art of fluorometry. After the fluorescent signalof the inert fluorescent tracer is detected and measured, it is knownhow to correlate that information with the concentration of the inertfluorescent tracer and once the concentration of the inert fluorescenttracer is known that information can be used to determine the amount oftreatment chemical present in the industrial water system and thatinformation can be used to optimize the operation of the industrialwater system.

The second aspect of the instant claimed invention is a method oftracing a corrosive material, comprising the steps of:

-   -   (a) providing an industrial water system and a corrosive        material that will be added to the water of the industrial water        system;    -   (b) placing in said corrosive material an inert fluorescent        tracer which has a detectable fluorescent signal when placed in        said corrosive material, wherein said inert fluorescent tracer        is added to said corrosive material in a known proportion;    -   (c) adding said corrosive material containing an inert        fluorescent tracer to the water of said industrial water system;    -   (d) providing a fluorometer capable of detecting the fluorescent        signal of said inert fluorescent tracer, wherein said        fluorometer has a sample cell that corrosive materials can be        placed in without rendering the sample cell unusable;    -   (e) using said fluorometer to detect and measure the fluorescent        signal of said fluorescent tracer in the water of said        industrial water system;    -   (f) using the detected and measured fluorescent signal to        determine how much of the corrosive material is present in the        water of said industrial water system; and optionally    -   (g) adjusting the operating parameters of said industrial water        system such that the amount of corrosive material present is        optimal for the operating conditions of said industrial water        system.

The inert tracers that can be used with the specific corrosive materialslisted in the first aspect of the instant claimed invention are the sameas those that can be used in the second aspect of the instant claimedinvention. The fluorometers that can be used in the second aspect of theinstant claimed invention are the same as those fluorometers that can beused in the first aspect of the instant claimed invention. How to set upand program a fluorometer and use it to measure the fluorescent signalof a fluorescent tracer is known to people of ordinary skill in the artof fluorometry. After the fluorescent signal of the tracer is detectedand measure, it is known how to correlate that information with theconcentration of the inert fluorescent tracer and once the concentrationof the inert fluorescent tracer is known that information can be used todetermine the amount of corrosive material present in the industrialwater system and that information can be used to optimize the operationof the industrial water system.

The third aspect of the instant claimed invention is a composition ofmatter comprising

-   -   c) from about 0.01 ppm to about 10,000 ppm of a compound        selected from the group consisting of 1,3,6,8-pyrene        tetrasulfonic acid and the known salts of 1,3,6,8-pyrene        tetrasulfonic acid,    -   b) a corrosive material, wherein said corrosive material is        selected from the group consisting of concentrated HCl,        concentrated H₂SO₄, glacial acetic acid, concentrated H₃PO₄ and        dimethylformamide; wherein concentrated HCl is at least about 37        wt. % HCl in water, concentrated H₂SO₄ is at least about 98 wt.        % H₂SO₄ in water, wherein concentrated H₃PO₄ is at least about        85 wt. % H₃PO₄ in water; wherein glacial acetic acid is at least        about 100 wt. % acetic acid in water and wherein        dimethylformamide is about 100 wt. % dimethylformamide.

The amount of 1,3,6,8-pyrene tetrasulfonic acid or a known salt of1,3,6,8-pyrene tetrasulfonic acid present in the corrosive material isfrom about 0.01 ppm to about 10,000 ppm, preferably from about 0.05 ppmto about 10 ppm and most preferably from about 0.1 ppm to about 1.0 ppm.The preferred compound is 1,3,6,8-pyrene tetrasulfonic acid, tetrasodiumsalt.

The fourth aspect of the instant claimed invention is a composition ofmatter comprising

-   -   a) from about 0.01 ppm to about 10,000 ppm of a compound        selected from the group consisting of 1,5-naphthalenedisulfonic        acid and the known salts of 1,5-naphthalenedisulfonic acid, and    -   b) a corrosive material, wherein said corrosive material is        selected from the group consisting of concentrated HCl and        concentrated H₃PO₄; wherein concentrated HCl is at least about        37 wt. % HCl in water and wherein concentrated H₃PO₄ is at least        about 85 wt. % H₃PO₄ in water.

The amount of 1,5-naphthalenedisulfonic acid or a known salt of1,5-naphthalenedisulfonic acid present in the corrosive material is fromabout 0.01 ppm to about 10,000 ppm, preferably from about 0.05 ppm toabout 10 ppm and most preferably from about 0.1 ppm to about 1.0 ppm.The preferred compound is 1,5-naphthalenedisulfonic acid, disodium salt.

The fifth aspect of the instant claimed invention is a composition ofmatter comprising

-   -   a) from about 0.01 ppm to about 10,000 ppm of a compound        selected from the group consisting of isomers of anthracene        disulfonic acid and salts thereof, and    -   b) a corrosive material, wherein said corrosive material is        selected from the group consisting of concentrated HCl,        concentrated H₃PO₄ and dimethylformamide; wherein concentrated        HCl is at least about 37 wt. % HCl in water, wherein        concentrated H₃PO₄ is at least about 85 wt. % H₃PO₄ in water and        wherein dimethylformamide is about 100 wt. % dimethylformamide.

The amount of isomer of anthracene disulfonic acid and salts thereofpresent in the corrosive material is from about 0.01 ppm to about 10,000ppm, preferably from about 0.05 ppm to about 10 ppm and most preferablyfrom about 0.1 ppm to about 1.0 ppm. The preferred isomers of anthracenedisulfonic acid are 1,5-anthracene disulfonic acid, magnesium salt,1,5-anthracene disulfonic acid, sodium salt and 1,8-anthracenedisulfonic acid sodium salt and mixtures thereof. The most preferredisomer of anthracene disulfonic acid is about a 2:1 mixture of1,5-anthracene disulfonic acid, sodium salt and 1,8-anthracenedisulfonic acid sodium salt.

The ability to trace a corrosive material is useful for the operation ofmany different industrial water systems.

The following examples are presented to be illustrative of the presentinvention and to teach one of ordinary skill how to make and use theinvention. These examples are not intended to limit the invention or itsprotection in any way.

EXAMPLES

Sample Preparation:

Fluorescent tracer solutions (see Table 1) were prepared by adding aspecified weighed amount of a stock solution of fluorescent tracer intoa corrosion-resistant 250 mL polypropylene bottle. Corrosive liquidsolution was added to the propylene bottle containing tracer solution toprovide a total volume of 100 mL. The fluorescent tracer and corrosiveliquid were mixed. The samples were stored at ambient temperature for atotal of 59 days. Test samples were taken at defined intervals from eachtraced corrosive liquid solution (initial, 4 days and 59 days) andfluorescence level was measured. TABLE 1 Stock Solution Amount TestSolution Fluorescent Tracer Concentration* Added Concentration1,5-naphthalenedisulfonic  130 ppm 0.31 gram  0.4 ppm acid, disodiumsalt 1,3,6,8-pyrenetetrasulfonic   10 ppm 1.00 gram  0.1 ppm acid,tetrasodium salt fluorescein, monopotassium  0.3 ppm 3.33 gram 0.010 ppmsalt 1,5-anthracenedisulfonic  109 ppm 0.74 gram  0.8 ppm acid,magnesium salt*Tracer concentration expressed as acid equivalent form

Fluorometer Selection and Set-Up for Detection of Fluorescent Signal ASPEX fluorometer (Model FluoroMax-2) was used to measure the fluorescentsignal and determine dosages of fluorescent tracers being tested incorrosive liquids. The fluorescent signal of each tracer was measured atthe excitation and emission wavelengths listed in Table 2. A rectangularquartz cuvette (10 mm×3 mm, inner dimensions) was used to hold thesample. Each combination of fluorescent tracer and corrosive liquid wasnormalized to 100% in the “initial sample” (Table 3) which was measuredwithin one hour after the tracer and corrosive liquid were mixed. In afew cases (Samples # 6, 16-19, and 21), the fluorescent tracer was notchemically stable with the corrosive liquid being tested and thefluorescent signal quickly decreased to virtually zero. In those cases,the “Initial Sample” was listed as having 0-1% fluorescence and thatcombination of tracer and corrosive fluid was judged as not acceptable.The fluorescence of the tracer and corrosive liquid solutions weretested again at 4 days and 59 elapsed time. The relative fluorescence ofthe samples measured at 4 days and 59 days are listed in Table 3. Thefluorescence of tracers which change by less than or equal to +/−10% (%relative fluorescence range=90 to 110%, as compared to initial sample)on Day 59 are given an acceptable rating and are defined as being inertover long time periods in the corrosive liquid environment being tested.% relative fluorescence readings on Days 4 and 59 which are greater than100% indicate an increase in % relative fluorescence, as compared toinitial sample. % relative fluorescence readings on Days 4 and 59 whichare less than 100% indicate an decrease in % relative fluorescence, ascompared to initial sample. TABLE 2 Excitation Emission FluorescentTracer Wavelength (nm) Wavelength (nm) 1,5-naphthalenedisulfonic 290 nm330 nm acid, disodium salt 1,3,6,8-pyrenetetrasulfonic 365 nm 400 nmacid, tetrasodium salt fluorescein, monopotassium 486 nm 515 nm salt1,5-anthracenedisulfonic acid, 365 nm 415 nm magnesium salt

TABLE 3 Relative Fluorescence over Time of Fluorescent Tracer inCorrosive Liquid Solution Relative Fluorescence Sample # Fluid TestedInitial 4 days 59 days Acceptable?* Compound #1 1 Water{circumflex over( )} 100 100 100 yes 2 Concentrated Hydrochloric Acid (˜37% aq. HCl) 10097 95 yes 3 Concentrated Sulfuric Acid (98% acid) 100 74 0 no 4 GlacialAcetic Acid (˜100% acid) >>100** N/A N/A no 5 Concentrated PhosphoricAcid (˜85% H3PO4) 100 98 95 yes 6 Concentrated Sodium Hydroxide (50%NaOH){circumflex over ( )}  1 0 0 no 7 DMF (100% Dimethylformamide) 100106 115 no Compound #2 8 Water{circumflex over ( )} 100 100 100 yes 9Concentrated Hydrochloric Acid (˜37% aq. HCl) 100 96 94 yes 10Concentrated Sulfuric Acid (98% acid) 100 102 102 yes 11 Glacial AceticAcid (˜100% acid) 100 102 102 yes 12 Concentrated Phosphoric Acid (˜85%H3PO4) 100 101 101 yes 13 Concentrated Sodium Hydroxide (50%NaOH){circumflex over ( )} 100 2 12 no 14 DMF (100% Dimethylformamide)100 99 96 yes Compound #3 These samples are kept in the dark to avoidlight degradation of the fluorescein molecule 15 Water{circumflex over( )} 100 100 100 yes 16 Concentrated Hydrochloric Acid (˜37% aq. HCl)  00 0 no 17 Concentrated Sulfuric Acid (98% acid)  0 0 0 no 18 GlacialAcetic Acid (˜100% acid)  0 0 0 no 19 Concentrated Phosphoric Acid (˜85%H3PO4)  0 0 0 no 20 Concentrated Sodium Hydroxide (50% NaOH){circumflexover ( )} 100 13 2 no 21 DMF (100% Dimethylformamide)  0 0 0 no1,5-anthracenedisulfonic acid, magnesium salt 22 Water{circumflex over( )} 100 100 100 yes 23 Concentrated Hydrochloric Acid (˜37% aq. HCl)100 97 92 yes 24 Concentrated Sulfuric Acid (98% acid) 100 53 15 no 25Glacial Acetic Acid (˜100% acid) 100 70 3 no 26 Concentrated PhosphoricAcid (˜85% H3PO4) 100 100 95 yes 27 Concentrated Sodium Hydroxide (50%NaOH){circumflex over ( )} 100 2 0 no 28 DMF (100% Dimethylformamide)100 98 95 yes*Acceptable value range is 90-110, which is +/− 10% of the initialreference point (100%)**Not acceptable due to very high background fluorescence{circumflex over ( )}Comparative Example, not an Example of theinvention

TABLE 4 Compilation of Final Results for Fluorescent Tracers inCorrosive Liquid Solutions Fluorescence Results from Day 59 Sample FluidTested (listed below) CMPD #1 CMPD #2 CMPD #3 ADSA Water{circumflex over( )} yes yes yes yes Concentrated HCl (˜37% aq. HCl) yes yes no yesConcentrated H2SO4 (98% acid) no yes no no Glacial Acetic Acid (˜100%acid) no yes no no Concentrated Phosphoric Acid (˜85% H3PO4) yes yes noyes Concentrated sodium hydroxide (50% NaOH){circumflex over ( )} no nono no DMF (100% dimethylformamide) no yes no yes {circumflex over( )}Comparative Example, not an Example of the invention No = not inert(results change by more than +/− 10% between initial and Day 59results), where the word “no” is used, the combination of fluorescenttracer and fluid tested is not an example of the instant claimedinvention. Yes = inert (results change by less than +/− 10% betweeninitial and Day 59 results) CMPD #1 = COMPOUND #1 =1,5-naphthalenedisulfonic acid, disodium salt CMPD #2 = COMPOUND #2 =1,3,6,8-pyrenetetrasulfonic acid, tetrasodium salt CMPD #3 = COMPOUND #3= fluorescein, monopotassium salt ADSA = 1,5-anthracenedisulfonic acid,magnesium salt Results: Compound Fluid Tested #1 #2 #3 #4Water{circumflex over ( )} yes yes yes yes Concentrated HCl (˜37% aq.HCl) yes yes no yes Concentrated H2SO4 (98% acid) no yes no no GlacialAcetic Acid (˜100% acid) no yes no no Concentrated Phosphoric Acid (˜85%H₃PO₄) yes yes no yes Concentrated sodium hydroxide (50%NaOH){circumflex over ( )} no no no no DMF (100% dimethylformamide) noyes no yes No = not inert (results change by more than +/− 10% betweeninitial and Day 59 results) Yes = inert (results change by less than +/−10% between initial and Day 59 results) {circumflex over ( )}comparativeexample, not an example of the invention #1 = 1,5-naphthalenedisulfonicacid, disodium salt available from Nalco #2 =1,3,6,8-pyrenetetrasulfonic acid, tetrasodium salt available from Nalcoas #3 = fluorescein, monopotassium salt available from Nalco #4 =1,5-anthracenedisulfonic acid, magnesium salt, available from Nalco

The present method has been described in an illustrative manner. Manymodifications and variations are possible in light of the aboveteachings. It is, therefore, to be understood that within the scope ofthe appended claims the invention may be practiced otherwise than asspecifically described.

1. The method of using an inert fluorescent tracer in an industrialwater system wherein the water of said industrial water system containsa certain amount of a corrosive material, comprising the steps of: A)providing an industrial water system wherein the water of saidindustrial water system contains a certain amount of a corrosivematerial; B) adding to the water of said industrial water system atreatment chemical wherein said treatment chemical includes an inertfluorescent tracer in a known proportion; C) providing a fluorometercapable of detecting the fluorescent signal of said inert fluorescenttracer, wherein said fluorometer has a sample cell that corrosivematerials can be placed in without rendering the sample cell unusable;D) using said fluorometer to detect and measure the fluorescent signalof said fluorescent tracer in the water of said industrial water system;E) using the detected and measured fluorescent signal to determine howmuch of the treatment chemical is present in the water of saidindustrial water system; and optionally; F) adjusting the operatingparameters of said industrial water system such that the amount oftreatment chemical present is optimal for the operating conditions ofsaid industrial water system.
 2. The method of claim 1 in which saidcorrosive material is selected from the group consisting of concentratedHCl, Concentrated H₂SO₄, Glacial Acetic Acid, Concentrated H₃PO₄anddimethylformamide, wherein said concentrated HCl is at least about 37wt. % HCl in water, said concentrated H₂SO₄ is at least about 98 wt. %H₂SO₄ in water, wherein said concentrated H₃PO₄ is at least about 85 wt.% H₃PO₄ in water; wherein said glacial acetic acid is at least about 100wt. % acetic acid in water and wherein said dimethylformamide is about100 wt. % dimethylformamide.
 3. The method of claim 2, wherein when saidcorrosive material is concentrated HCl, said inert tracer is selectedfrom the group consisting of (a) 1,5-naphthalenedisulfonic acid and theknown salts of 1,5-naphthalenedisulfonic acid, (b)1,3,6,8-pyrenetetrasulfonic acid, and the known salts of1,3,6,8-pyrenetetrasulfonic acid, and (c) isomers of anthracenedisulfonic acid and salts thereof.
 4. The method of claim 2, whereinwhen said corrosive material is concentrated H₂SO₄, said inert tracer is1,3,6,8-pyrenetetrasulfonic acid, tetrasodium salt.
 5. The method ofclaim 2, wherein when said corrosive material is concentrated glacialacetic acid said inert tracer is 1,3,6,8-pyrenetetrasulfonic acid,tetrasodium salt.
 6. The method of claim 2, wherein when said corrosivematerial is concentrated H₃PO₄, said inert tracer is selected from thegroup consisting of (a) 1,5-naphthalenedisulfonic acid and the knownsalts of 1,5-naphthalenedisulfonic acid, (b) 1,3,6,8-pyrenetetrasulfonicacid and the known salts of 1,3,6,8-pyrenetetrasulfonic acid, and (c)isomers of anthracene disulfonic acid and salts thereof.
 7. The methodof claim 2, wherein when said corrosive material is dimethylformamide,said inert tracer is selected from the group consisting of1,3,6,8-pyrenetetrasulfonic acid, the known salts of1,3,6,8-pyrenetetrasulfonic acid, isomers of anthracene disulfonic acidand salts thereof.
 8. A method of tracing a corrosive material,comprising the steps of: (a) providing an industrial water system and acorrosive material that will be present in the water of the industrialwater system; (b) placing in said corrosive material an inertfluorescent tracer which has a detectable fluorescent signal when placedin said corrosive material, wherein said inert fluorescent tracer isadded to said corrosive material in a known proportion; (c) adding saidcorrosive material containing an inert fluorescent tracer to the waterof said industrial water system; (d) providing a fluorometer capable ofdetecting the fluorescent signal of said inert fluorescent tracer,wherein said fluorometer has a sample cell that corrosive materials canbe placed in without rendering the sample cell unusable; (e) using saidfluorometer to detect and measure the fluorescent signal of saidfluorescent tracer in the water of said industrial water system; (f)using the detected and measured fluorescent signal to determine how muchof the corrosive material is present in the water of said industrialwater system; and optionally (g) adjusting the operating parameters ofsaid industrial water system such that the amount of corrosive materialpresent is optimal for the operating conditions of said industrial watersystem.
 9. A composition of matter comprising a) from about 0.01 ppm toabout 10,000 ppm of a compound selected from the group consisting of1,3,6,8-pyrene tetrasulfonic acid and the known salts of 1,3,6,8-pyrenetetrasulfonic acid. b) a corrosive material, wherein said corrosivematerial is selected from the group consisting of concentrated HCl,concentrated H₂SO₄, glacial acetic acid, concentrated H₃PO₄ anddimethylformamide; wherein concentrated HCl is at least about 37 wt. %HCl in water, concentrated H₂SO₄ is at least about 98 wt. % H₂SO₄ inwater, wherein concentrated H₃PO₄ is at least about 85 wt. % H₃PO₄ inwater; wherein glacial acetic acid is at least about 100 wt. % aceticacid in water and wherein dimethylformamide is about 100 wt. %dimethylformamide.
 10. The composition of claim 9 wherein the compoundis 1,3,6,8-pyrenetetrasulfonic acid, tetrasodium salt.
 11. A compositionof matter comprising a) from about 0.01 ppm to about 10,000 ppm of acompound selected from the group consisting of 1,5-naphthalenedisulfonicacid and the known salts of 1,5-naphthalenedisulfonic acid, and b) acorrosive material, wherein said corrosive material is selected from thegroup consisting of concentrated HCl and concentrated H₃PO₄; whereinconcentrated HCl is at least about 37 wt. % HCl in water and whereinconcentrated H₃PO₄ is at least about 85 wt. % H₃PO₄ in water.
 12. Thecomposition of claim 11 wherein the compound is1,5-naphthalenedisulfonic acid, disodium salt.
 13. A composition ofmatter comprising a) from about 0.01 ppm to about 10,000 ppm of acompound selected from the group consisting of isomers of anthracenedisulfonic acid and salts thereof, and b) a corrosive material, whereinsaid corrosive material is selected from the group consisting ofconcentrated HCl, concentrated H₃PO₄ and dimethylformamide; whereinconcentrated HCl is at least about 37 wt. % HCl in water, whereinconcentrated H₃PO₄ is at least about 85 wt. % H₃PO₄ in water and whereindimethylformamide is about 100 wt. % dimethylformamide.
 14. Thecomposition of claim 13 wherein the compound is about a 2:1 mixture of1,5-anthracene disulfonic acid, disodium salt and 1,8-anthracenedisulfonic acid, disodium salt.